<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let arr = [1,2,3,4];


        // 返回数组中是否含有某个值的布尔结果。
        // let bool = arr.includes(8);

        // console.log(bool);


        
    </script>
</body>
</html>